This invention relates to taping machines, and more particularly to tape machines for automatically sealing packages or containers by applying an adhesive tape to a package.
Heretofore, large bags containing bulk chemicals have tended to leak materials after filling of the bags. Because of the leakage, it has been necessary to tape the package closed by hand labor.
Although it will be appreciated that the invention has broader applications, the particular type of packaging which the present invention addresses, relates to 50 pound sacks or bags of chemicals. The package container or bag has a generally elongated rectangular shape and is constructed of heavy paper. The package container, may or may not, contain a plastic liner insert. The package container is preformed and presealed and has an opening in a fold at one of its bottom ends. In the bottom flap of the package container which defines the opening to the bag is a plastic tubular member through which a nozzle is inserted. The chemicals are injected into the package container through the tubular member to the proper volume or weight. When the proper volume or weight is otained, the injection nozzle is withdrawn and the flap with the plastic tubular member closes and is intended to seal the contents within the package container. Unfortunately, the subsequent handling of the filled package container, more often than not, causes the flap and tubular member to open so that materials leak from the package container.
In an effort to resolve the problem of leakage, the package container is typically provided with an additional seal by means of adhesive plastic sealing tape which attaches to the package container and generally fits over the side panels and the bottom of the package container. It is not necessary to have a neat appearing seal and thus when a rectangular strip of sealing tape is applied to the package container, it typically will attach to the front and rear sides and the bottom and adhers to itself and to the package container. Generally speaking, the sealing of package containers by hand involves two laborers and attendant time to perform the sealing operation on each package container in an assembly line.
The present invention provides a method and apparatus for automatically applying a sealing tape to a corner of a package container or bag.
The system of the present invention involves a belt conveyer for transporting filled bags through a tape sealing apparatus. There are side by side conveyer belts means with one of the conveyer belts means being continuous from end to end of the apparatus. The other conveyer belt means is divided into separate belt conveyer sections so as to form an opening along its length to accomodate the sealing operation performed on the bag. At the forward and rearward ends of conveyers belt means are transverse forward and rearward gate members which respectively stop a bag from entering the apparatus while the sealing operation occurs and for stopping a bag in position for a sealing operation to occur in the apparatus. After a bag passes through the forward gate member it actuates a first trigger mechanism which lowers both gate members. Thereafter, the bag actuates a second trigger mechanism which stops the conveyer belts and starts the sealing operation. Also as a bag is transported by the conveyer belts toward the rearward gate member, a depending adhesive strip of tape with its ahdesive side facing the oncoming bag first engages the top end surface of the bag and then is dragged across the upper side of the bag until the bag stops at the rearward gate member. At this position, a free end of an adhesive tape strip is positioned over the upper side of the bag. The strip of tape also extends outwardly from the bag, that is over the side of the bag. When the sealing operation is commenced by the bag reaching the rearward gate member, a vertically reciprocating taping mechanism, which is located rearward of the rear end of the bag, moves downwardly. As the tape mechanism moves downwardly, a roller on the tape mechanism engages the upper surface of the adhesive tape on the upper side of the bag and presses the tape firmly onto the upper surface bag. The roller, as the tape mechanism is moved downwardly, is pivoted on a frame so that the strip of tape is unlocked with respect to a locking mechanism and so that a roll of tape can unroll while the tape is applied to the bag. The roller, after engaging the upper side of the bag, moves from the upper side of the bag to the bottom end of the bag and presses the tape to the bottom end of the bag. Subsequently, the roller is displaced to a position below the bag. At this point of the operation, the tape is adhered to the upper surface of the bag, the bottom end surface of the bag and has a section disposed below the bottom end surface of the bag. Also, there is an overlapping adhesive portion of the tape extending outwardly of the side of the bag. At the bottom of the travel of the tape mechanism, a switch is triggered to actuate a pivotally mounted wiper arm located to one side of the conveyer belts. The wiper arm is pivotally moved to bring a U-shaped wiper member into a positon rearward of the bag and behind the semi-attached tape. The U-shaped wiper member has rubber blated wipers and is sized to conform to the dimensions of the bag so that as the wiper member engages the tape, the tape is attached to the upper, lower and side surfaces of the bag by the wipers applying pressure to attach the tape onto the corner and sides of the bag. When the wiper member is pivoted into position between the opening defined by the conveyer sections, it is located behind the tape and the wiper member is moved longitudinally along the bag to accomplish the sealing operation. At the same time that the wiper blade is moved, a blade cutter below the bag severs the tape below the bottom surface of the bag so as to leave a depending attached strip of tape available for the next operation. At the end of the longitudinal stroke of the wiper member to press the tape to the corner of the bag, another switch is operated to pivot the wiper arm outwardly to its initial position. As the wiper arm moves outwardly toward its initial position, a trigger switch actuates the tape mechanism to return the tape mechanism to its vertical, upward starting position and actuates another switch to open the gate members and start the conveyer belts to permit the next bag to enter for a sealing operation.